Pre-Formulation Tool to Rapidly Predict the Stability of Monoclonal Antibodies

Pre-formulation tool to rapidly predict the stability of monoclonal antibodies

S. Hedberg*, J.Y.Y Heng*, D.R. Williams* and J. Liddell**

ABSTRACT

Protein-protein molecular interactions are known to be involved in protein solution aggregation behaviour and are a common issue for the manufacturing of therapeutic proteins such as mAbs. Much effort has been employed to gain a better understanding of aggregation. However, the mechanisms leading to protein aggregation are still not fully understood. The osmotic second virial coefficient (B₂₂) is a fundamental physiochemical property that describes protein-protein interactions solution, which can be a useful tool for predicting the aggregation propensity of proteins.

One way of predicting aggregation propensity is self-interaction chromatography (SIC), which has demonstrated recent promise as a tool for the better understanding of phase behaviour of proteins. Another technique, cross-interaction chromatography (CIC), has shown to be an even more high-throughput technique than its predecessor with possibly the same capabilities.

The first part of this paper is a scale-down SIC study of therapeutic mAbs from laboratory scale macro-columns to micro-scale columns, which enables the use of micrograms or milligrams of mAb for B₂₂ determinations in order to obtain a complete formulation screen.

The second part of this work presents an extensive formulation study of a mAbs system, varying pH and salt, as well as the presence of different stabilisers and different external factors known to induce aggregation. The B₂₂ and B₂₃ values determined from the formulation study are then correlated with aggregation kinetics obtained from size-exclusion chromatography and dynamic light scattering. It was shown that over all test conditions good correlations could especially be found between B₂₂ and aggregation rate.

The third part of the study includes investigation of conformational changes of the monoclonal antibodies. The B₂₂ data previously obtained were directly correlated with the conformational changes observed in the mAb to create a predictive tool that can detect any early conformational changes.

In summary this work intends to gain a better understanding of the fundamental mechanisms of aggregation and to develop a more predictive capability by studying the chromatogram output resulting from the self- and cross-interactions between the same or different proteins.

REFERENCES

Hedberg, S. H. M., Heng, J. Y. Y., Williams, D. R. & Liddell, J. M. (2016). Micro Scale Self-Interaction Chromatography of Proteins: A Mab Case-Study. Journal of Chromatography A, 1434, 57-63.

Quigley, A. & Williams, D. R. (2015). The Second Virial Coefficient as a Predictor of Protein Aggregation Propensity: A Self-Interaction Chromatography Study. European Journal of Pharmaceutics and Biopharmaceutics, 96, 282-290.